Diffusion Couple with Uniform Composition Input

In this tutorial, the diffusion simulation on a diffusion couple with uniform composition at each side (as shown in Figure 1) is carried out. The annealing temperature is 1000 °C and the duration is 2 hours. “Region_1” represents the left-hand side of this diffusion couple, and “Region_2” represents the right-hand side of this diffusion couple. Each region is 100 μm and the simulation box is discretized to 100 grids.

Figure 1:  Initial conditions of the diffusion couple simulation

Set up Initial Condition for Diffusion Simulation

In order to set the above conditions in PanDiffusion, click through the menu bar "PanDiffusion→ Diffusion Simulation", or by clicking on the Toolbar., a popup window will show and allow user to set up calculation conditions (as shown in Figure 2 and Figure 3).

Figure 2:  Dialog window for user to set the composition of Region_1

Figure 3:  Dialog window for user to set the composition of Region_2 and diffusion simulation conditions

Click Region_1 to set up the composition of the left-hand side as shown in Figure 2, and click Region_2 to set up composition of the right-hand side as shown in Figure 3. Details regarding the interface design will be described in Section Settings in General Diffusion Simulation. Constant annealing temperature is set as 1000 °C, and annealing time is 2 hours.

As is highlighted by the green box in Figure 3, the simulation condition can be saved to a “.pbfx” file by selecting “Save Condition”. The saved condition can be loaded by clicking “Load Condition” for the future usage. When a condition is loaded from “.pbfx” file, the settings in the GUI are updated accordingly.

Simulation Results

Click OK button in Figure 3 to start the simulation after the initial condition is set properly. The simulation result is displayed in Figure 4.

In this case, only the initial and final composition profiles are presented: the dotted lines with sharp interface are for the initial stage and the solid lines with smooth interface are for the final stage.

Figure 4:  Output graph showing the initial and final composition profiles

Customize Simulation Results

As all other calculations available in Pandat™, upon the completion of the diffusion simulation, a default table of properties (such as time, temperature, grid size, distance, composition distribution, volume fraction and chemical potential) is automatically generated and a default graph of composition profiles is displayed. User can refer to Section Graph and Section Table to learn how to customize simulated graph and table.